The organic light-emitting diode (OLED) is also known as an organic electro-laser display, or an organic light-emitting semiconductor. The OLED display technology adopts a very thin organic material coating and a glass substrate, where when current passes through the glass substrate, the organic material glows, and the OLED display technology is widely applied in mobile phones, digital video cameras, notebook computers and televisions. The basic structure of an OLED device is to sandwich an entire structural layer between two electrodes to form a sandwich structure, and the entire structural layer includes: a hole transport layer (HTL), an emitting layer (EML) and an electron transport layer (ETL). For selection of an anode material, the material itself must have a high work function and light transmissivity, and an indium tin oxide (ITO) transparent conductive film having a high work function of 4.5 eV to 5.3 eV, stable properties and high light transmittance is widely used in an anode. However, indium, which is one of the elements constituting ITO, is a scarce metal with a low global reserve, and the production of ITO requires expensive equipment. Therefore, it is necessary to find a transparent electrode material which can replace ITO.
The transparent conductive electrode needs to have a low sheet resistance (about 100 Ω/cm2), have a high carrier concentration (about 1020/cm3), and have a high light transmittance (for the visible light at 550 nm, the transmission rate >85%). At present, a material which can be used as the transparent conductive electrode includes a thin metal film, a thin oxide film, or a thin polymer film. The thickness of the thin conductive transparent metal film needs to be controlled between 3-15 nm to ensure a high light transmittance of the transparent electrode. However, due to a metal surface effect and impurities, when a thin metal film having a thickness less than 10 nm is actually prepared, an island-like structure is easily formed to remarkably improve the resistivity of the thin film, and the undulating island structure causes scattering of an incident light, thereby affecting the transmittance of the thin film. The metal which is commonly used as a thin transparent metal film includes Ag, Au, Cu, Al, Cr, etc. Although having the advantage of low electrical resistance, a pure metal, when used as the thin transparent conductive film, has the disadvantages of being readily oxidizable, having insufficient light transmission, having no flexibility, and having a poor mechanical strength. In order to change the disadvantage of the thin metal film of having poor mechanical properties, thin metal-mesh films, thin nanowire mesh films, and the like thin films are used as the thin transparent conductive films, but it is required to introduce a precursor and conditions such as a high temperature in the preparation of the thin metal-mesh films and the thin nanowire films, leading to a high cost in industrial applications, and thus the thin metal-mesh films and the thin nanowire films cannot be generally commercialized. The thin metal oxide film is the thin transparent conductive film commonly used in the industry field because of its advantages of easy preparation, good light transmittance, and various types. Common thin transparent metal oxide films include SnO2, ZnO, In2O3, GaO, Cu2O, Zn2SnO4, ZnSnO3, MgIn2O4, GaInO3, (GaIn)2O3, Zn2In2O5, In4Sn3O12, and Cd2SnO4, doped systems developed on the basis of the thin metal oxide film include SnO2:Sb, SnO2:F, and In2O3:Sn, and the photoelectric and mechanical properties of the conductive thin film are changed by changing the doped components. However, due to the poor mechanical properties of the metal oxide, the thin metal oxide film cannot be applied to a device such as a flexible thin film solar cell, a flexible touch screen display, and an electronic skin, and has a non-ideal effect in terms of improving the light transmittance while enhancing conductive properties.